Add a browsing data counter factory on iOS

ios/chrome/browser/browsing_data/browsing_data_counter_wrapper.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ios/chrome/browser/browsing_data/browsing_data_counter_wrapper.h"
+
+#include "base/callback.h"
+#include "base/memory/ptr_util.h"
+#include "components/prefs/pref_service.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.h"
+
+// static
+std::unique_ptr<BrowsingDataCounterWrapper>
+BrowsingDataCounterWrapper::CreateCounterWrapper(
+    const char* pref_name,
+    ios::ChromeBrowserState* browser_state,
+    PrefService* pref_service,
+    const UpdateUICallback& update_ui_callback) {
+  std::unique_ptr<browsing_data::BrowsingDataCounter> counter =
+      IOSBrowsingDataCounterFactory::GetForBrowserStateAndPref(browser_state,
+                                                               pref_name);
+  if (!counter)
+    return nullptr;
+  return base::WrapUnique<BrowsingDataCounterWrapper>(
+      new BrowsingDataCounterWrapper(std::move(counter), pref_service,
+                                     update_ui_callback));
+}
+
+BrowsingDataCounterWrapper::~BrowsingDataCounterWrapper() {}
+
+void BrowsingDataCounterWrapper::RestartCounter() {
+  counter_->Restart();
+}
+
+BrowsingDataCounterWrapper::BrowsingDataCounterWrapper(
+    std::unique_ptr<browsing_data::BrowsingDataCounter> counter,
+    PrefService* pref_service,
+    const UpdateUICallback& update_ui_callback)
+    : counter_(std::move(counter)), update_ui_callback_(update_ui_callback) {
+  counter_->Init(pref_service,
+                 base::Bind(&BrowsingDataCounterWrapper::UpdateWithResult,
+                            base::Unretained(this)));
+}
+
+void BrowsingDataCounterWrapper::UpdateWithResult(
+    std::unique_ptr<browsing_data::BrowsingDataCounter::Result> result) {
+  update_ui_callback_.Run(*result.get());
+}